Extendable mes for cross-amhs transportation

ABSTRACT

A cross-semiconductor fabrication (fab) facility transportation system and method for cross-fab transportation is provided. An exemplary method for cross-fab transportation includes providing a unified control unit that facilitates transportation of one or more wafers across a plurality of wafer fabrication facilities (“fabs”). The unified control unit facilitates selecting a wafer at a first location in a first automated material handling system (“AMHS”) of a first fab for transfer to a second AMHS of a second fab; selecting a second location within the second AMHS of the second fab; selecting a route for transferring the wafer between the first location and the second location; and issuing instructions to the first and second fabs, such that the wafer is transferred from the first location to the second location.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/745,521, filed May 8, 2007, now U.S. Pat. No. ______, issued ______,the entire disclosure of which is incorporated herein by reference.

BACKGROUND

The manufacture of semiconductor devices involves the performance of aseries of process steps using a variety of high tech production andmetrology tools in a certain order and often within a certain period oftime. The primary function of a wafer logistics system in a waferfabrication facility, or “fab,” is to deliver the wafers to each of thetools at the right time, as well as to track the location and status ofthe wafers throughout the process. Automated material handling systems(“AMHS”) are applied to wafer fabs to carry out the automated functionsmore efficiently, consistently, and safely than can be done via manualmeans. The fabrication process often results in the need for cross-floorand cross-phase transportation within a single fab and/or cross-fabtransportation between fabs.

When a wafer carrier, such as a front opening unified pod (“FOUP”),containing wafers is to be transferred, a manufacturing execution system(“MES”) determines to what destination in the fab the wafer carriershould be transferred. Once the destination decision has been made, theMES sends a transfer request to a material control system (“MCS”), whichcalculates a detailed transportation route using a route search engineand then notifies a transfer manager to execute the transferstep-by-step. However, typical MES and MCS systems are limited to asingle fab and cannot process cross-fab and/or cross-AMHS transportationrequests. The MES and MCS systems of one fab are often unable tocommunicate with the AMHS of a separate fab. In that regard, differentfabs may have different AMHS vendors and communication protocols.

Although existing systems and methods have been generally adequate fortheir intended purposes, they have not been entirely satisfactory in allrespects.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 is a schematic diagram illustrating a factory automation systemfor facilitating cross-fab wafer transportation according to oneembodiment of the present disclosure.

FIG. 2 is a schematic diagram illustrating a factory automation systemfor facilitating cross-fab wafer transportation according to anotherembodiment of the present disclosure.

FIG. 3 is a schematic diagram illustrating a master material controlsystem (MCS) according to one embodiment of the present disclosure foruse with the systems of FIGS. 1 and 2.

FIG. 4 is a schematic diagram illustrating at least a portion of amanufacturing facility including a factory automation system and aplurality of fabs according to one embodiment of the present disclosure.

FIG. 5 is a schematic diagram illustrating a cross-fab transportationsystem according to one embodiment of the present disclosure.

FIG. 6 is a schematic diagram illustrating a cross-fab transportationsystem according to another embodiment of the present disclosure.

FIG. 7 is a schematic diagram illustrating a cross-fab transportationsystem and a cross-fab wafer transportation process according to oneembodiment of the present disclosure.

FIG. 8 is a flowchart illustrating a method of transferring a waferbetween fabs as illustrated in FIG. 7.

FIG. 9 is a schematic diagram illustrating a cross-fab transportationsystem and a cross-fab wafer transportation process according to anotherembodiment of the present disclosure.

FIG. 10 is a flowchart illustrating a method of transferring a waferbetween fabs as illustrated in FIG. 9.

FIG. 11 is a flowchart illustrating a method of transporting a waferbetween a plurality of fabs according to one embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

It is understood that the following disclosure provides many differentembodiments, or examples, capable of implementing different features.Specific examples of components and arrangements are described below tosimplify and thus clarify the present disclosure. These are, of course,merely examples and are not intended to be limiting. In many instances,the features of one embodiment may be combined with the features ofother embodiments. In addition, the present disclosure may repeatreference numerals and/or letters in the various exemplary embodiments.This repetition is for the purpose of simplicity and clarity and doesnot in itself dictate a relationship between the various embodimentsand/or configurations discussed.

A semiconductor foundry may include a plurality of fabs. Duringprocessing, a wafer may be transferred between the plurality of fabs fordifferent steps of the manufacturing process. A “cross-fab transfer”involves the transfer of a wafer carrier, or front opening unified pod(“FOUP”), from one fab to another. A “cross-AMHS transfer” involves thetransfer of a wafer carrier, or FOUP, from one automated materialhandling system (“AMHS”) to another AMHS, regardless of whether theAMHSs are separate systems within a single fab or systems in separatefabs. Each fab may include multiple phases and/or multiple floors. Inthat regard, in some embodiments, the fab may be what is referred to asa “gigafab.” A “cross-floor transfer job” involves the transfer of awafer carrier, or FOUP, from one floor to another. A “cross-phasetransfer job” involves the transfer of a wafer carrier, or FOUP, fromone phase to another.

Each phase of a fab includes a plurality of bays that may includeprocessing tools or equipment. The equipment within each bay may beinterconnected by an intrabay overhead transport (“OHT”) system. Thebays may be interconnected with the other bays via an interbay OHTsystem. As will be familiar to those of ordinary skill in the relevantart, the intrabay OHT systems and the interbay OHT system compriseoverhead tracks on which OHT vehicles transport FOUPs containing lots ofwafers to be processed to and from the equipment of the bays, often viastockers. In addition to or in lieu of the OHT systems, each fab mayinclude an intrabay and/or interbay overhead shuttle (“OHS”) system.Each fab may also include a cross-floor transportation system. Thecross-floor transportation system may include lifters and/or othermechanisms for implementing cross-floor transfers of FOUPs.

Referring now to FIG. 1, shown therein is a simplified diagram of afactory automation system 100 for facilitating cross-fab wafertransportation according to one embodiment of the present disclosure.The system 100 includes a fab 102, a fab 104, and a fab 106. The fab 102includes a manufacturing execution system (“MES”) 108, a MCS 110, and anAMHS 112. The fab 104 includes a MES 114, a MCS 116, and an AMHS 118.The fab 106 includes a MES 120, a MCS 122, and an AMHS 122. It isunderstood that the MESs 108, 114, and 120; the MCSs 110, 116, and 122;and the AMHSs 112, 118, and 124 may include a plurality of components asis known in the art. For example, but without limitation, each AMHS 112,118, and 124 may includes a plurality of control modules, such as areticule stocker controller, a stocker controller, an overhead buffercontroller, an inter-bay OHS controller, an intra-bay OHT controller,and/or a lifter controller. The AMHSs 112, 118, and 124 may includeadditional, fewer, and different control modules in some embodiments.

The system 100 also includes a unified control unit 126. The unifiedcontrol unit 126 is configured to facilitate and/or organizetransportation of wafers among and between the fabs 102, 104, and 106.The unified control unit 126 is configured to communicate with each ofthe fabs 102, 104, and 106. In that regard, the unified control unit 126may act as a server for receiving and providing information and/orinstructions to each of the fabs. The unified control unit may also actas a communications link between fabs such that the MES, MCS, and/orother systems of each fab may communicate directly with the systems ofanother fab. The unified control unit 126 may comprise hardware,software, or combinations of hardware and software. In some embodiments,the unified control unit 126 is a stand alone unit separate from theMES, MCS, and other systems of each fab. In other embodiments, theunified control unit 126 is a component or part of at least one of thefabs. In at least some embodiments, communication between the unifiedcontrol unit 126 and the fabs 102, 104, and 106 is by Common ObjectRequest Broker Architecture (“CORBA”). Further, communication betweencomponents of the unified control unit 126 and communication betweencomponents of the fabs 102, 104, and 106 may utilize CORBA. However, inother embodiments other communication protocols and/or middleware may beused.

In the current embodiment, the unified control unit 126 includes an MCSmaster 128. The MCS master 128 is configured to manage and communicatewith the MCSs 110, 116, and 122 of the fabs 102, 104, and 106,respectively. In particular, the MCS master 128 is configured tocommunicate with each of the MCSs 110, 116, and 122 such that across-AMHS transfer can be synchronized across the different AMHSs 112,118, and 124 by sending appropriate transfer request signals to theMCSs. To that end, the MCS master 128 may be in communication with adatabase or a plurality of databases containing information regardingthe MES and AMHS mapping for each fab, the available transfer patternsfor each fab, the bridge settings and available transfer patternsbetween fabs, and/or other information related to transferring waferswithin each fab and between the plurality of fabs.

The unified control unit 126 is configured to synchronize the MCSs 110,116, and 122 and/or the AMHSs 112, 118, and 124 of the different fabs102, 104, and 106 to facilitate movement of a wafer lot among thedifferent fabs. In that regard, the AMHSs 112, 118, and 124 may be fromthe same vendor or from different vendors. Where the unified controlunit 126 is configured to facilitate movement of a wafer lot betweenAMHSs from different vendors, the unified control unit is capable ofheterogeneous AMHS integration. Heterogeneous AMHS integration can beadvantageous as it allows cross-AMHS transportation among AMHSs fromdifferent vendors in addition to cross-AMHS transportation between AMHSsfrom the same vendor. For example, heterogeneous AMHS integration canallow each fab of a semiconductor foundry the flexibility to choose anAMHS vendor or other transport system from different vendors and not betied to a single vendor. Also, automated cross-AMHS transportation ingeneral provides a savings of man power and can provide alternativeproduction routes when a fab or AMHS is down or non-operational for somereason. Thus, manufacturing may continue even where a fab or AMHS is notproperly functioning. The unified control unit 126 can extend AMHSscalability beyond a single fab to the entire manufacturing process,including gigafab applications. Also, the unified control unit 126 canbe used to define and maintain MES and AMHS relationships acrossmultiple fabs and/or AMHSs.

Referring now to FIG. 2, shown therein is a simplified diagram of afactory automation system 101 for facilitating cross-fab wafertransportation according to another embodiment of the presentdisclosure. In several aspects, the system 101 is substantially similarto the system 100 described above. The system 101 includes a fab 102, afab 104, and a fab 106. The fab 102 includes a MES 108, a MCS 110, andan AMHS 112. The fab 104 includes a MES 114, a MCS 116, and an AMHS 118.The fab 106 includes a MES 120, a MCS 122, and an AMHS 124. The system101 also includes a unified control unit 126. The unified control unit126 is configured to facilitate and/or organize transportation of wafersamong and between the fabs 102, 104, and 106. In the current embodiment,the unified control unit 126 includes a MCS master 128 and a central MES130. The MCS master 128 is configured to manage the MCSs 110, 116, and122 of the fabs 102, 104, and 106, respectively. The central MES 130 isin communication with the MCS master 128 and the MESs 108, 114, and 120of each of the fabs 102, 104, and 106. The central MES 130 is configuredto define and maintain MES and AMHS relations between and among the fabs102, 104, and 106. Thus, in some embodiments, the central MES 130provides MES and AMHS architecture across the fabs 102, 104, and 106 foruse in selecting appropriate transfer routes for wafer lots within thefabs.

The system 101 also includes an interpreter 132 between the unifiedcontrol unit 126 and the fab 102, an interpreter 134 between the unifiedcontrol unit 126 and the fab 104, and an interpreter 136 between theunified control unit 126 and the fab 106. Since the MCSs 110, 116, and122 and the AMHSs 112, 118, and 124 of each of the fabs 102, 104, and106 may be from a different manufacturer or vendor, the system 101 isconfigured to communicate with the various protocols for each vendor.Thus, in the current embodiment, the system includes the interpreters132, 134, and 136. The terms interpreter and translator may be usedinterchangeably herein to refer to an application that converts a firstprotocol or communication language into a second protocol orcommunication language. The interpreters 132, 134, and 136 translate thesignals generated from the unified control unit 126 into the appropriatecommunication language for the MES, MCS, and/or AMHS that will receivethe signal. In that regard, a single interpreter may be used acrossmultiple MESs, MCSs, and/or AMHSs where the systems will use the samecommunication language. Thus, it is contemplated that the system 101 mayhave an interpreter for each protocol or communications language that isshared among all of the systems that utilize that protocol. It isunderstood that the interpreters 132, 134, and 136 may be softwareapplications, hardware, and/or combinations of software and hardware.Further, the interpreters 132, 134, and 136 may be a component of theunified control unit 126, a component of a fab, a stand-alone unit,and/or combinations thereof.

Referring now to FIG. 3, shown therein is a schematic diagram of an MCSMaster 128 according to one embodiment of the present disclosure for usewith the systems 100 and 101 described above. As illustrated, the MCSMaster 128 includes bridge settings 138, transfer patterns 140, MES andAMHS mapping 142, a cross-AMHS control unit 144, and a transactiondispatcher 146. In that regard, includes as used in the previoussentence is intended to include having access to. For example, it isfully contemplated that one or more of the bridge settings 138, transferpatterns 140, and MES and AMHS mapping 142 may be stored in a databaseaccessible by the MCS Master 128. Thus, the MCS Master 128 may be incommunication with such a database rather than storing or maintainingthe bridge settings 138, transfer patterns 140, and MES and AMHS mapping142 itself. On the other hand, in some embodiments, the MCS Master 128may store and/or maintain the bridge settings 138, transfer patterns140, and/or MES and AMHS mapping 142 itself.

The bridge settings 138 represent the connections between AMHSs and/orfabs. In some embodiments, the unified control unit 126 may define abridge between the AMHSs and/or fabs. In that regard, the bridge may bea piece of hardware and/or a series of hardware components such as astocker, conveyor, overhead system, and/or combinations thereof. On theother hand, the bridge may simply be a defined location within an OHT orOHS. Where the bridge is a defined point within an existing system, itmay be referred to as a virtual point. The bridge serves as theconnection between the AMHSs such that at the bridge control of a FOUPor wafer lot may be passed from one AMHS to another. Thus, in someembodiments, the bridge is an area where two or more AMHSs may operatetogether. In this manner, the FOUP may be transferred across multipleAMHSs by passing control of the FOUP from one AMHS to another at eachbridge location. A bridge connecting one AMHS to another AMHS mayaccommodate one-way traffic and/or two-way traffic. That is, the bridgemay facilitate transferring a FOUP from the first AMHS to the secondAMHS, from the second AMHS to the first AMHS, or both. Where the bridgeis configured for one-way transfers, an additional bridge may connectthe two AMHSs such that FOUPs can be transferred both ways between theAMHSs. In some embodiments, a bridge may connect more than two AMHSs toone another.

The transfer patterns 140 represent the available routes fortransferring a FOUP between a first position in a first AMHS and asecond position in a second AMHS. In some embodiments, the transferpatterns are dynamic and may be updated by such factors as static anddynamic traffic conditions, lot information, lot priority, availableroutes, route distances, maintenance schedules, and/or other factors.The MES and AMHS mapping 142 provide static information regarding theavailable routing within the individual fabs and AMHSs that is combinedto form a global mapping across the multiple MESs and AMHSs. In thatregard, the MES and AMHS mapping 142 may include the location of varioustools and equipment among the fabs and AMHSs that can be utilized inroute planning and assessment. While in some of the embodimentsdescribed below, there appears to be a single route between positions,this is simply for the sake of clarity and example and should not beconsidered limiting. Rather, it is fully contemplated that there couldbe multiple routes for transferring a FOUP between AMHSs from the firstposition to the second position. In that regard, the systems 100, 101may include apparatus and methods for route selection as described inU.S. Pat. No. 7,356,378 entitled “Method and System for Smart VehicleRoute Selection,” hereby incorporated by reference in its entirety, thatmay be adapted for cross-AMHS transportation. Further, the systems 100,101 may also include an integrated transportation control system asdescribed in U.S. Patent Application Publication No. 2008/0021593entitled “Integrated Transportation Control for Wafer FabricationFacility,” filed Jul. 19, 2006, hereby incorporated by reference in itsentirety.

The cross-AMHS control unit 144 and the transaction dispatcher 146 areconfigured to provide the transfer request signals to each of the MCSs.In that regard, transfer of a FOUP between AMHSs may be broken down intosub-routes comprised of transfers within a single AMHS. In someembodiments, the transfer may be broken down into sub-routes comprisedof transfers within a single AMHS and transfers across a bridge.Multiple sub-routes may be linked together to create the full transferroute. In some embodiments, the transfer patterns 140 are based onavailable combinations of sub-routes for achieving the desired transfer.Thus, the cross-AMHS control unit 144 and the transaction dispatcher 146may be configured to synchronize the multiple AMHSs to facilitate thetransfer of the wafer. In some embodiments, the cross-AMHS control unit144 is configured to provide a cross-AMHS transfer request indicative ofa selected transfer route. The transaction dispatcher 146 may beconfigured to then communicate the corresponding sub-route transferrequests associated with the cross-AMHS transfer requests to theindividual AMHSs for execution. By coordinating the sub-route transferrequests, the entire cross-AMHS transfer request can be properlyexecuted. In some embodiments, the transaction dispatcher 146 sends thetransfer request through an interpreter appropriate for the individualAMHS. In other embodiments, the transaction dispatcher 146 may functionas an interpreter itself.

While the systems 100, 101 have been described as having a particularcombination of components, it is understood that the systems 100, 101may have fewer or greater components as would be apparent to one skilledin the art. In addition, the functions of some of the various componentsmay be combined into a single component and/or functions of a singlecomponent may be split out into multiple components. In otherembodiments, the systems 100, 101 may include additional fabs and/orAMHSs in communication with the unified control unit 126. Cross-faband/or cross-AMHS transportation can be extended to the additional fabsand/or AMHSs in a manner similar to that described above with respect tofabs 102, 104, and 106. Further, in some embodiments, the systems 100,101 may be configured for use with only two fabs or AMHSs.

Referring now to FIG. 4, shown therein is a schematic diagramillustrating at least a portion of a manufacturing facility including afactory automation system and a plurality of fabs according to oneembodiment of the present disclosure. In particular, FIG. 4 provides aschematic illustration of aspects of the systems 100, 101 describedabove in use with fabs 102, 104, and 106. In that regard, the samereference numerals have been utilized to refer to similar devices andsystems, however no limitation is intended thereby.

As shown, FIG. 4 includes a fab 102, a fab 104, and a fab 106. The fab102 includes a MES 108, a MCS 110, and an AMHS 112. The fab 104 includesa MES 114, a MCS 116, and an AMHS 118. The fab 106 includes a MES 120, aMCS 122, and an AMHS 124. A unified control unit 126 is in communicationwith the fabs 102, 104, and 106. As described above, the unified controlunit 126 is configured to facilitate and/or organize transportation ofwafers among and between the fabs 102, 104, and 106. In particular, theunified control unit 126 is configured to facilitate transportation ofwafer lots between the equipment 148, including processing tools,stockers, and other equipment, of the various AMHSs 112, 118, and 124.In the current embodiment, the wafer lots are transferred via FOUPs 150between the equipment 148.

A bridge 152 connects the fab 102 to the fab 104 and, in particular, theAMHS 112 to the AMHS 118. In that regard, the bridge includes a section154 for transferring FOUPs from the fab 102 to the fab 104 and a section156 for transferring FOUPs from the fab 104 to the fab 102. Similarly, abridge 158 connects the fab 104 to the fab 106 and, in particular, theAMHS 118 to the AMHS 124. The bridge 158 may be substantially similar tothe bridge 152 in some aspects, including having a section fortransferring FOUPS from the fab 104 to the fab 106 and a section fortransferring FOUPs from the fab 106 to the fab 104. However, in thecurrent embodiment, the bridge 158 also includes equipment 148 as shown.In some embodiments, the equipment 148 is a stocker for temporarilyholding a FOUP. In that regard, one of the AMHSs 118 or 124 may place aFOUP in the stocker such that the other AMHS can pick up the FOUP andcontinue the transfer process. In other embodiments, the equipment 148is not a stocker, but other processing tool and/or storage device.

Referring now to FIG. 5, shown therein is a schematic diagramillustrating a cross-fab transportation system according to oneembodiment of the present disclosure. In particular, FIG. 5 shows apossible transportation system for cross-AMHS transfers between fabs102, 104, and 106. As shown in FIG. 5, an overhead shuttle system 160(“OHS”) connects the fabs 102, 104, and 106 to one another. In thatregard, the OHS 160 includes a bridge point 162 for transfers from fab102 to fab 104, a bridge point 164 for transfers from fab 104 to fab102, a bridge point 166 for transfers from fab 104 to fab 106, and abridge point 168 for transfers from fab 106 to fab 104. The bridgepoints 162, 164, 166, and 168 may be designated points of the OHS 160where control of a FOUP may be transferred from one AMHS to another. Thebridge points 162, 164, 166, and 168 may be virtual points designatedwithin the OHS 160. That is, the bridge points 162, 164, 166, and 168 donot require any additional structures, mechanisms, or equipment be addedto or connected to the OHS 160 to function as the bridge between thefabs. In other embodiments, the bridge points 162, 164, 166, and/or 168may include additional structures, mechanisms, or equipment that areconnected to the OHS 160.

As shown, in the current embodiment the bridge points 162, 164, 166, and168 are one-way. That is, each bridge point 162, 164, 166, and 168facilitates transfers in only one direction between the fabs. Thus, atransfer between fab 102 and fab 104, represented by arrow 170, may beaccomplished by an AMHS of fab 102 carrying a FOUP to bridge point 162and then an AMHS of fab 104 picking up the FOUP from the bridge point162. The bridge point 162 may be referred to as transfer point AS1EQ2 interms of the AMHS of fab 102. The bridge point 162 may be referred to astransfer point BS1EQ1 in terms of the AMHS of fab 104. Similarly, atransfer between fab 104 and fab 106, represented by arrow 172, may beaccomplished by an AMHS of fab 104 carrying a FOUP to bridge point 166and then an AMHS of fab 106 picking up the FOUP from the bridge point166. The bridge point 166 may be referred to as transfer point BS1EQ2 interms of the AMHS of fab 104. The bridge point 166 may be referred to astransfer point CS1EQ1 in terms of the AMHS of fab 106.

Further, a transfer between fab 106 and fab 104, represented by arrow174, may be accomplished by an AMHS of fab 106 carrying a FOUP to bridgepoint 168 and then an AMHS of fab 104 picking up the FOUP from thebridge point 168. The bridge point 168 may be referred to as transferpoint CS1EQ2 in terms of the AMHS of fab 106. The bridge point 166 maybe referred to as transfer point BS1EQ3 in terms of the AMHS of fab 104.Similarly, a transfer between fab 104 and fab 102, represented by arrow176, may be accomplished by an AMHS of fab 104 carrying a FOUP to bridgepoint 164 and then an AMHS of fab 102 picking up the FOUP from thebridge point 164. The bridge point 164 may be referred to as transferpoint BS1EQ4 in terms of the AMHS of fab 104. The bridge point 164 maybe referred to as transfer point AS1EQ2 in terms of the AMHS of fab 102.

Referring now to FIG. 6, shown therein is a schematic diagramillustrating a cross-fab transportation system according to anotherembodiment of the present disclosure. In particular, FIG. 6 shows apossible transportation system for cross-AMHS transfers between fabs102, 104, and 106. As shown in FIG. 6, fab 102 includes an OHT 180, fab104 includes an OHT 182, and fab 106 includes an OHT 184. A bridge point186 and a bridge point 188 connect the OHT 180 of fab 102 to a stocker190. In some embodiments, the stocker 190 may be a conveyor. In otherembodiments, the stocker 190 may be replaced with other types ofequipment. The stocker 190, in turn, is connected to the OHT 182 of fab104 via unit nodes 192 and 194, as shown. In some embodiments, thebridge points 186 and 188, the stocker 190, and the unit nodes 192 and194 collectively act as a bridge between the AMHSs of fab 102 and fab104. In other embodiments, the stocker 190 and the unit nodes 192 and194 are part of the fab 104. Similarly, a bridge point 196 and a bridgepoint 198 connect the OHT 182 of fab 104 to a stocker 200. The stocker200, in turn, is connected to the OHT 184 of fab 106 via unit nodes 202and 204, as shown. In some embodiments, the bridge points 196 and 198,the stocker 200, and the unit nodes 202 and 204 collectively act as abridge between the AMHSs of fab 104 and fab 106. In other embodiments,the stocker 200 and the unit nodes 202 and 204 are part of the fab 106.

A transfer between fab 102 and fab 104, represented by arrow 206, may beaccomplished by the AMHS of fab 102, such as OHT 180, carrying a FOUP tobridge point 186 where the FOUP is moved to stocker 190. The FOUP may bemoved to stocker 190 from the bridge point 186 by the AMHS of fab 102,the AMHS of fab 104, a separate bridge transportation system (notshown), and/or combinations thereof. Then the FOUP is transferred fromthe stocker 190 to the AMHS of fab 104, such as OHT 182, via unit node192. The bridge point 186 may be referred to as transfer pointATXEQ1:P01 in terms of the AMHS of fab 102. The bridge point 186 may bereferred to as transfer point BTXSK1:P01 (PGV IN) in terms of the AMHSof fab 104. Similarly, a transfer between fab 104 and fab 106,represented by arrow 208, may be accomplished by the AMHS of fab 104,such as OHT 182, carrying a FOUP to bridge point 196 where the FOUP ismoved to stocker 200. The FOUP may be moved to stocker 200 from thebridge point 196 by the AMHS of fab 104, the AMHS of fab 106, a separatebridge transportation system (not shown), and/or combinations thereof.The FOUP is transferred from the stocker 200 to the AMHS of fab 106,such as OHT 184, via unit node 202. The bridge point 196 may be referredto as transfer point BTXEQ1:P01 in terms of the AMHS of fab 104. Thebridge point 196 may be referred to as transfer point CTXSK1:P01 (PGVIN) in terms of the AMHS of fab 106.

Further, a transfer between fab 106 and fab 104, represented by arrow210, may begin with the AMHS of fab 106, such as OHT 184, carrying aFOUP to stocker 200 via the unit node 204. The FOUP may be accessiblevia bridge point 198 from the stocker 200. In some embodiments, the FOUPis moved from the stocker 200 to bridge point 198 by the AMHS of fab106, the AMHS of fab 104, a separate bridge transportation system (notshown), and/or combinations thereof. The FOUP is transferred from thestocker 200 and/or the bridge point 198 by the AMHS of fab 104, such asOHT 182. The bridge point 198 may be referred to as transfer pointCTXSK1:P02 (PGV OUT) in terms of the AMHS of fab 106. The bridge point198 may be referred to as transfer point BTXEQ1:P02 in terms of the AMHSof fab 104. A transfer between fab 104 and fab 102, represented by arrow212, may begin with the AMHS of fab 104, such as OHT 182, carrying aFOUP to stocker 190 via the unit node 194. The FOUP may be accessiblevia bridge point 188 from the stocker 190. In some embodiments, the FOUPis moved from the stocker 190 to bridge point 188 by the AMHS of fab104, the AMHS of fab 102, a separate bridge transportation system (notshown), and/or combinations thereof. The FOUP is transferred from thestocker 190 and/or the bridge point 188 by the AMHS of fab 102, such asOHT 180. The bridge point 188 may be referred to as transfer pointBTXSK1:P02 (PGV OUT) in terms of the AMHS of fab 104. The bridge point198 may be referred to as transfer point ATXEQ1:P02 in terms of the AMHSof fab 102.

Referring now to FIGS. 7 and 8, a system and method for cross-AMHSand/or cross-fab transfer of a wafer lot will be described. FIG. 7 is aschematic diagram illustrating a cross-fab transportation system and across-fab wafer transportation process according to one embodiment ofthe present disclosure. FIG. 8 is flowchart illustrating a method oftransferring a wafer between fabs according to one embodiment of thepresent disclosure and corresponding to the process illustrated in FIG.7. As shown in FIG. 7, the fabs 102, 104, and 106 may be substantiallysimilar to those shown in FIG. 4 described above. In that regard, fab102 is shown with a master material control system 214 (“MMCS1”), fab104 is shown with a master material control system 216 (“MMCS2”), andfab 106 is shown with a master material control system 218 (“MMCS3”). Inthat regard, the MMCS1 214, MMCS2 216, and MMCS3 218 may be parts of aunified control unit 126 and, in particular, a master material controlsystem 128. Thus, communications between the MMCSs 214, 216, and 218 maybe within a single MMCS. Similarly, communications between the MES,MMCS, MCS, and/or AMHS of a fab may include communications between anexternal system such as a unified control unit. However, it is fullycontemplated that the MMCSs 214, 216, and 218 may be part of the fabs102, 104, and 106, as shown.

Referring more specifically to FIG. 7, a FOUP 150 may be transferredfrom a position 220 within fab 102 to a position 222 within fab 106. Oneexample, of a method 250 for transporting the FOUP 150 between thepositions 220 and 222 will now be described with reference to FIGS. 7and 8. The method 250 begins with step 252 where a transfer request isprovided and communicated to MMCS1 214. The transfer request may beinitiated from a unified control unit, an MES of a fab, or a manualrequest. In that regard, the request may be a general transfer requestfrom one type of equipment to another. The unified control unit, theMES, and/or the user may select the actual equipment location wherethere is more than one available equipment location suitable for thetransfer. In that regard, the selected location may be based on numerousfactors including lot condition, lot priority, traffic conditions,available routes, length of the available routes, and/or otherparameters. In the current embodiment, the transfer request hasrequested that the FOUP 150 be transported from position 220 within fab102 to position 222 within fab 106.

The method 250 continues with step 254 in which the MMCS1 214 determinesan appropriate route for transferring the FOUP between the currentposition 220 and the final position 222 and communicates that route tothe MCS 110. In that regard, the MMCS1 214 may be part of a unifiedcontrol unit that determines the overall route for the FOUP 150, suchthat the MMCS1 serves to provide a sub-route of the overall route forexecution within fab 102. That is, in some embodiments, the MMCS1 214may serve to provide desired route instructions for the FOUP 150 withinfab 102 only. In the current embodiment, the MMCS1 214 may provide therequisite route information for transferring the FOUP from position 220to the bridge 152 between fab 102 and fab 104. Once the MMCS1 214 hasdetermined an appropriate route for the FOUP 150 within fab 102, thestep 254 continues with the corresponding route instructions beingcommunicated from the MMCS1 214 to the MCS 110. As described above, thecommunication of the route instructions from the MMCS1 to the MCS 110may include the use of an interpreter in some embodiments to convert ageneral communications protocol (e.g., CORBA) into a vendor specificprotocol associated with the MCS 110.

After the route instructions have been communicated to the MCS 110, themethod 250 continues with step 256 in which the MCS 110 relays the routeinstructions to the AMHS 112 for execution. After the AMHS 112 hastransferred the FOUP 150 according to the route instructions, the method250 continues with step 258 in which the AMHS signals to the MCS 110that the transfer within fab 102 is complete. In the current embodiment,the AMHS 112 indicates that the FOUP 150 has been transferred to thebridge 152 as requested. The MCS 110 in turn relays notice of thecompleted transfer to the MMCS1 214 at step 260. The method 250continues with step 262 where the MMCS1 214 transfers the notice of thecompleted transfer to the MMCS2 216. As described above, the MMCS1 214and the MMCS2 216 may be parts of a single MMCS. In such embodiments,the step 262 may be virtual and/or omitted because providing notice ofthe completed transfer to MMCS1 214 may also provide notice to MMCS2216.

Once the MMCS2 216 receives notice that the FOUP 150 has beentransferred to bridge 152, the method 250 continues with step 264 inwhich the MMCS2 216 determines an appropriate route for transferring theFOUP between the current position at bridge 152 and the final position222 and communicates that route to the MCS 116. In that regard, theMMCS2 216 may be part of a unified control unit that has determined theoverall route for the FOUP 150, such that the MMCS2 serves to provide asub-route of the overall route for execution within fab 104. In thecurrent embodiment, the MMCS2 216 may provide the requisite routeinformation for transferring the FOUP from the bridge 152 to the bridge158 between fab 104 and fab 106. Once the MMCS2 216 has determined anappropriate route for the FOUP 150 within fab 104, the step 264continues with the corresponding route instructions being communicatedfrom the MMCS2 216 to the MCS 116. As described above, the communicationof the route instructions from the MMCS2 216 to the MCS 116 may includethe use of an interpreter.

After the route instructions have been communicated to the MCS 116, themethod 250 continues with step 266 in which the MCS 116 relays the routeinstructions to the AMHS 118 for execution. After the AMHS 118 hastransferred the FOUP 150 according to the route instructions, the method250 continues with step 268 in which the AMHS signals to the MCS 116that the transfer within fab 104 is complete. In the current embodiment,the AMHS 118 indicates that the FOUP 150 has been transferred to thebridge 158 as requested. The MCS 116 in turn relays notice of thecompleted transfer to the MMCS2 216 at step 270. The method 250continues with step 272 where the MMCS2 216 transfers the notice of thecompleted transfer to the MMCS3 218. As described above, the MMCS2 216and the MMCS3 218 may be parts of a single MMCS. In such embodiments,the step 272 may be virtual and/or omitted because providing notice ofthe completed transfer to MMCS2 216 may also provide notice to MMCS3218.

Once the MMCS3 218 receives notice that the FOUP 150 has beentransferred to bridge 158, the method 250 continues with step 274 inwhich the MMCS3 218 determines an appropriate route for transferring theFOUP between the current position at bridge 158 and the final position222 and communicates that route to the MCS 122. In that regard, theMMCS3 218 may be part of a unified control unit that has determined theoverall route for the FOUP 150, such that the MMCS3 serves to provide asub-route of the overall route for execution within fab 106. In thecurrent embodiment, the MMCS2 216 may provide the requisite routeinformation for transferring the FOUP from the bridge 158 to theposition 222. Once the MMCS3 218 has determined an appropriate route forthe FOUP 150 within fab 106, the step 274 continues with thecorresponding route instructions being communicated from the MMCS3 218to the MCS 122. As described above, the communication of the routeinstructions from the MMCS3 218 to the MCS 122 may include the use of aninterpreter.

After the route instructions have been communicated to the MCS 122, themethod 250 continues with step 276 in which the MCS 122 relays the routeinstructions to the AMHS 124 for execution. After the AMHS 124 hastransferred the FOUP 150 according to the route instructions, the method250 continues with step 278 in which the AMHS signals to the MCS 122that the transfer within fab 106 is complete. In the current embodiment,the AMHS 124 indicates that the FOUP 150 has been transferred to theposition 222 as requested. The MCS 122 in turn relays notice of thecompleted transfer to the MMCS3 218 at step 280. In the currentembodiment, the method 250 continues with step 282 where the MMCS3 218transfers the notice of the completed transfer to the MES 120 of fab106. In some embodiments, the MES 120 may be in communication with orpart of a unified control unit and, in particular, in communication withor part of a central MES. In some such embodiments, the central MES maybe in communication with an MMCS that includes MMCS3 218. In thatregard, the step 282 may be virtual or omitted in some embodimentsbecause providing notice of the completed transfer to MMCS3 218 may alsoprovide notice to the central MES. In this manner, the FOUP 150 may betransferred between points 220 and 222 within different AMHSs and, inthe current embodiment, within different fabs using an automated system.

Referring now to FIGS. 9 and 10, a system and method for cross-AMHSand/or cross-fab transfer of a wafer lot will be described. Inparticular, FIGS. 9 and 10 illustrate a method of modifying a transferrequest and/or rescheduling a transfer request after initiating thetransfer. Modifying and/or rescheduling the transfer request may be aresult of a system error, a manual request, changes in availableroute/traffic information, and/or combinations thereof. FIG. 9 is aschematic diagram illustrating a cross-fab transportation system and across-fab wafer transportation process according to one embodiment ofthe present disclosure. FIG. 10 is a flowchart illustrating a method oftransferring a wafer between fabs according to one embodiment of thepresent disclosure and corresponding to the process illustrated in FIG.9. As shown in FIG. 9, the fabs 102, 104, and 106 may be substantiallysimilar to those shown in FIG. 7 and described above.

Referring more specifically to FIG. 9, a transfer request may requestthat a FOUP 150 be transferred from a position 220 within fab 102 to aposition 222 within fab 106. One example of a method 300 for modifyingthe transfer of the FOUP 150 between the positions 220 and 222 will nowbe described with reference to FIGS. 9 and 10. The method 300 beginswith step 302 where a transfer request is provided and communicated toMMCS1 214. The transfer request may be initiated from a unified controlunit, an MES of a fab, or a manual request. In that regard, the requestmay be a general transfer request from one type of equipment to another.The unified control unit, the MES, and/or the user may select the actualequipment location where there is more than one available equipmentlocation suitable for the transfer. In that regard, the selectedlocation may be based on numerous factors including lot condition, lotpriority, traffic conditions, available routes, length of the availableroutes, and/or other parameters. In the current embodiment, the transferrequest has requested that the FOUP 150 be transported from position 220within fab 102 to position 222 within fab 106.

The method 300 continues with step 304 in which the MMCS1 214 determinesan appropriate route for transferring the FOUP between the currentposition 220 and the final position 222 and communicates that route tothe MCS 110. In that regard, the MMCS1 214 may be part of a unifiedcontrol unit that determines the overall route for the FOUP 150, suchthat the MMCS1 serves to provide a sub-route of the overall route forexecution within fab 102. That is, in some embodiments the MMCS1 214 mayserve to provide desired route instructions for the FOUP 150 within fab102 only. In the current embodiment, the MMCS1 214 may provide therequisite route information for transferring the FOUP from position 220to the bridge 152 between fab 102 and fab 104. Once the MMCS1 214 hasdetermined an appropriate route for the FOUP 150 within fab 102, thestep 304 continues with the corresponding route instructions beingcommunicated from the MMCS1 214 to the MCS 110. As described above, thecommunication of the route instructions from the MMCS1 to the MCS 110may include the use of an interpreter in some embodiments to convert ageneral communications protocol (e.g., CORBA) into a vendor specificprotocol associated with the MCS 110.

After the route instructions have been communicated to the MCS 110, themethod 300 continues with step 306 in which the MCS 110 relays the routeinstructions to the AMHS 112 for execution. After the AMHS 112 hastransferred the FOUP 150 according to the route instructions, the method300 continues with step 308 in which the AMHS signals to the MCS 110that the transfer within fab 102 is complete. In the current embodiment,the AMHS 112 indicates that the FOUP 150 has been transferred to thebridge 152 as requested. The MCS 110 in turn relays notice of thecompleted transfer to the MMCS1 214 at step 310. The method 300continues with step 312 where the MMCS1 214 transfers the notice of thecompleted transfer to the MMCS2 216. As described above, the MMCS1 214and the MMCS2 216 may be parts of a single MMCS. In such embodiments,the step 312 may be virtual and/or omitted because providing notice ofthe completed transfer to MMCS1 214 may also provide notice to MMCS2216.

Once the MMCS2 216 receives notice that the FOUP 150 has beentransferred to bridge 152, the method 300 continues with step 314 inwhich the MMCS2 216 determines an appropriate route for transferring theFOUP between the current position at bridge 152 and the final position222 and communicates that route to the MCS 116. In that regard, theMMCS2 216 may be part of a unified control unit that has determined theoverall route for the FOUP 150, such that the MMCS2 serves to provide asub-route of the overall route for execution within fab 104. In thecurrent embodiment, the MMCS2 216 may provide the requisite routeinformation for transferring the FOUP from the bridge 152 to the bridge158 between fab 104 and fab 106. Once the MMCS2 216 has determined anappropriate route for the FOUP 150 within fab 104, the step 314continues with the corresponding route instructions being communicatedfrom the MMCS2 216 to the MCS 116. As described above, the communicationof the route instructions from the MMCS2 216 to the MCS 116 may includethe use of an interpreter.

After the route instructions have been communicated to the MCS 116, themethod 300 continues with step 316 in which the MCS 116 relays the routeinstructions to the AMHS 118 for execution. After the AMHS 118 hastransferred the FOUP 150 according to the route instructions, the method300 continues with step 318 in which the AMHS signals to the MCS 116that the transfer within fab 104 is complete. In the current embodiment,the AMHS 118 indicates that the FOUP 150 has been transferred to thebridge 158 as requested. The MCS 116 in turn relays notice of thecompleted transfer to the MMCS2 216 at step 320.

The method 300 continues with step 322 where the MMCS2 216 providemodified route information for transferring the FOUP 150. In thatregard, the modified route info may be in response to an error in thetransfer execution, manual entry, traffic conditions, equipmentavailability, and/or other conditions. In the current embodiment, theMMCS2 216 indicates that the FOUP 150 should be transferred from bridge158 to a position 323 within fab 104. Position 323 may be a holdingposition within a stocker or other equipment and/or the position 323 maybe another type of equipment. Again, the MMCS2 216 may provide therequisite route information for transferring the FOUP from the bridge158 to the position 323. Once the MMCS2 216 has determined anappropriate route for the FOUP 150 within fab 104, the step 322continues with the corresponding modified route instructions beingcommunicated from the MMCS2 216 to the MCS 116. After the modified routeinstructions have been communicated to the MCS 116, the method 300continues with step 324 in which the MCS 116 relays the routeinstructions to the AMHS 118 for execution. After the AMHS 118 hastransferred the FOUP 150 according to the route instructions, the method300 continues with step 326 in which the AMHS signals to the MCS 116that the transfer within fab 104 is complete. In the current embodiment,the AMHS 118 indicates that the FOUP 150 has been transferred to theposition 323 as requested. The MCS 116 in turn relays notice of thecompleted transfer to the MMCS2 216 at step 328. In some embodiments,the FOUP 150 may be later transferred from position 323 to position 222according to another transfer request.

Referring now to FIG. 11, shown therein is an illustrative node 400 forimplementing embodiments of the methods described above. Node 400includes a microprocessor 402, an input device 404, a storage device406, a video controller 408, a system memory 410, a display 414, and acommunication device 416 all interconnected by one or more buses 412.The storage device 406 could be a floppy drive, hard drive, CD-ROM,optical drive, or any other form of storage device. In addition, thestorage device 406 may be capable of receiving a floppy disk, CD-ROM,DVD-ROM, or any other form of computer-readable medium that may containcomputer-executable instructions. Further, communication device 416could be a modem, network card, or any other device to enable the nodeto communicate with other nodes. It is understood that any node couldrepresent a plurality of interconnected (whether by intranet orInternet) computer systems, including without limitation, personalcomputers, mainframes, PDAs, and cell phones.

A computer system typically includes at least hardware capable ofexecuting machine readable instructions, as well as the software forexecuting acts (typically machine-readable instructions) that produce adesired result. In addition, a computer system may include hybrids ofhardware and software, as well as computer sub-systems.

Hardware generally includes at least processor-capable platforms, suchas client-machines (also known as personal computers or servers), andhand-held processing devices (such as smart phones, personal digitalassistants (PDAs), or personal computing devices (PCDs), for example).Further, hardware may include any physical device that is capable ofstoring machine-readable instructions, such as memory or other datastorage devices. Other forms of hardware include hardware sub-systems,including transfer devices such as modems, modem cards, ports, and portcards, for example.

Software includes any machine code stored in any memory medium, such asRAM or ROM, and machine code stored on other devices (such as floppydisks, flash memory, or a CD ROM, for example). Software may includesource or object code, for example. In addition, software encompassesany set of instructions capable of being executed in a client machine orserver.

Combinations of software and hardware could also be used for providingenhanced functionality and performance for certain embodiments of thepresent disclosure. One example is to directly manufacture softwarefunctions into a silicon chip. Accordingly, it should be understood thatcombinations of hardware and software are also included within thedefinition of a computer system and are thus envisioned by the presentdisclosure as possible equivalent structures and equivalent methods.

Computer-readable mediums include passive data storage, such as a randomaccess memory (RAM) as well as semi-permanent data storage such as acompact disk read only memory (CD-ROM). In addition, an embodiment ofthe present disclosure may be embodied in the RAM of a computer totransform a standard computer into a new specific computing machine.

Data structures are defined organizations of data that may enable anembodiment of the present disclosure. For example, a data structure mayprovide an organization of data, or an organization of executable code.Data signals could be carried across transmission mediums and store andtransport various data structures, and, thus, may be used to transportan embodiment of the present disclosure.

The system may be designed to work on any specific architecture. Forexample, the system may be executed on a single computer, local areanetworks, client-server networks, wide area networks, internets,hand-held and other portable and wireless devices and networks.

A database may be any standard or proprietary database software, such asOracle, Microsoft Access, SyBase, or DBase II, for example. The databasemay have fields, records, data, and other database elements that may beassociated through database specific software. Additionally, data may bemapped. Mapping is the process of associating one data entry withanother data entry. For example, the data contained in the location of acharacter file can be mapped to a field in a second table. The physicallocation of the database is not limiting, and the database may bedistributed. For example, the database may exist remotely from theserver, and run on a separate platform. Further, the database may beaccessible across the Internet. Note that more than one database may beimplemented.

The foregoing has outlined features of several embodiments so that thoseskilled in the art may better understand the detailed description thatfollows. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein. Itis understood that various different combinations of the above-listedprocessing steps can be used in combination or in parallel. Also,features illustrated and discussed above with respect to someembodiments can be combined with features illustrated and discussedabove with respect to other embodiments. Those skilled in the art shouldalso realize that such equivalent constructions do not depart from thespirit and scope of the present disclosure, and that they may makevarious changes, substitutions and alterations herein without departingfrom the spirit and scope of the present disclosure.

1. A method of implementing a factory automation system for automated wafer transfers across a plurality of wafer fabrication facilities (“fabs”), the method comprising: providing a unified control unit that facilitates transportation of one or more wafers across the plurality of fabs, wherein the unified control unit facilitates: defining a bridge connecting a first automated material handling system (“AMHS”) of a first fab and a second AMHS of a second fab; selecting a wafer located in the first AMHS of the first fab for transfer to the second AMHS of the second fab, the wafer positioned at a first location; selecting a second location within the second AMHS of the second fab as a destination for the wafer; selecting a route for transferring the wafer between the first location and the second location, the route including at least a portion of the bridge; transferring the wafer from the first location to the bridge; and transferring the wafer from the bridge to the second location.
 2. The method of claim 1 wherein facilitating transportation of the wafer from the first location to the second location comprises communicating with a first material control system associated with the first AMHS and a second material control system associated with the second AMHS.
 3. The method of claim 1 wherein selecting the route for transferring the wafer comprises selecting a first sub-route within the first AMHS, selecting a bridge sub-route between the first AMHS and the second AMHS, and selecting a second sub-route within the second AMHS.
 4. The method of claim 1 further comprising: dispatching a first route transfer request to the first AMHS using a first communication protocol; and dispatching a second route transfer request to the second AMHS using a second communication protocol.
 5. The method of claim 4 wherein: dispatching the first route transfer request includes dispatching a first unified route transfer request and using a first translator to translate the first unified route transfer request into the first communication protocol; and dispatching the second route transfer request includes dispatching a second unified route transfer request and using a second translator to translate the second unified route transfer request into the second communication protocol, the second communication protocol being different than the first communication protocol.
 6. The method of claim 4 further comprising utilizing a transaction dispatcher to dispatch the first and second route transfer requests.
 7. A factory automation system for wafer transportation across automatic material handling systems (“AMHSs”), the factory automation system comprising: a first material control system (“MCS”) and an associated first AMHS; a second MCS and an associated second AMHS; a bridge connecting the first AMHS and the second AMHS, the bridge configured to allow a front opening unified pod (“FOUP”) to travel between the first AMHS and the second AMHS; and a unified control unit in communication with the first and second MCSs, the unified control unit for coordinating transfers of the FOUP between the first and second AMHSs.
 8. The system of claim 7 wherein the first MCS and the first AMHS communicate with the unified control unit with a first communication protocol and the second MCS and the second AMHS communicate with the unified control unit with a second communication protocol.
 9. The system of claim 7 further comprising: a third MCS and an associated third AMHS; and another bridge connecting the second AMHS and the third AMHS, the another bridge configured to allow the FOUP to travel between the second AMHS and the third AMHS, wherein the unified control unit is in communication with the third MCS, allowing the unified control unit to coordinate transfers of the FOUP between the first, second, and third AMHSs.
 10. The system of claim 9 further comprising: a first translator for translating a communication from the unified control unit into a first communication protocol for use by the first MCS and the first AMHS; a second translator for translating a communication from the unified control unit into a second communication protocol for use by the second MCS and the second AMHS; and a third translator for translating a communication from the unified control unit into a third communication protocol for use by the third MCS and the third AMHS.
 11. The system of claim 9 wherein the unified control unit includes a master MCS that communicates with the first and second MCSs.
 12. A method comprising: providing a unified control unit that facilitates transportation of one or more wafers across a plurality of wafer fabrication facilities (“fabs”), wherein the unified control unit facilitates: selecting a wafer at a first location in a first automated material handling system (“AMHS”) of a first fab for transfer to a second AMHS of a second fab; selecting a second location within the second AMHS of the second fab; selecting a route for transferring the wafer between the first location and the second location; and issuing instructions to the first and second fabs, such that the wafer is transferred from the first location to the second location.
 13. The method of claim 12 wherein issuing instructions to the first and second fabs, such that the wafer is transferred from the first location to the second location, includes: utilizing a first interpreter to translate signals from the unified control unit to the first fab; and utilizing a second interpreter to translate signals from the unified control unit to the second fab.
 14. The method of claim 12 wherein selecting a route for transferring the wafer between the first location and the second location includes: determining a first sub-route for transferring the wafer between the first location and an intermediate location; and determining a second sub-route for transferring the wafer between the intermediate location and the second location.
 15. The method of claim 14 wherein issuing instructions to the first and second fabs, such that the wafer is transferred from the first location to the second location includes: communicating a first sub-route transfer request to the first AMHS; and communicating a second sub-route transfer request to the second AMHS.
 16. The method of claim 15 further comprising: after communicating the first sub-route transfer request to the first AMHS, transferring the wafer along the first sub-route from the first location to an intermediate location; notifying the unified control unit that the wafer has been transferred to the intermediate location; after communicating the second sub-route to the second AMHS, transferring the wafer along the second sub-route from the intermediate location to the second location; and notifying the unified control unit that the wafer has been transferred to the second location.
 17. The method of claim 15 wherein: communicating the first sub-route transfer request to the first AMHS includes utilizing a first communication protocol; and communicating a second sub-route transfer request to the second AMHS includes utilizing a second communication protocol different than the first communication protocol.
 18. The method of claim 12 further comprising: modifying the route for transferring the wafer between the first location and the second location; and issuing instructions to the first and second fabs, such that the wafer is transferred along the modified route.
 19. The method of claim 12 wherein selecting the route for transferring the wafer between the first location and the second location includes evaluating a plurality of routes for transferring the wafer between the first and second locations.
 20. The method of claim 19 evaluating the plurality of routes includes evaluating at least one of traffic conditions, lot information, lot priority, routes distances, and maintenance schedules. 